THE PINEAL SYSTEM OF FISHES 



211 



Fig. 147. — Longitudinal Median Section through the Pineal Diverticulum 

 of an Embryo of a Sturgeon (Acipenser), showing the Continuity 

 and Similarity of Structure of the Wall of the Diverticulum with 

 the ependymal roof of the interbrain, and the position and extent 

 of the Posterior and Habenular Commissures. (After Studnicka.) 



c.h. : habenular commissure. Epi. 



c.p. : posterior commissure. p.o. . 



c.t. : connective tissue. r. pi. 

 epen. : ependyma. 



epidermis, 

 pineal organ. 

 : recessus pinealis. 



rS c 



C^-z I m 



Fig. 148. — Section through the Proximal Part of the Stalk of the Pineal 

 Organ of a Sturgeon (Acipenser sturio), highly magnified. (After 

 Studnicka.) 



e.l.m. : external limiting membrane. 



ep. c. : clear ependymal cell without cilia. 



jr. c. : free cell in lumen of stalk. 



g.c. : ganglion cell. 



gl. c. : neuroglial cell. 



n.j. : nerve-fibres. 



p. pr. : protoplasmic process. 

 /. sc. : deeply stained cell resembling the sensory cells of the retina in the lamprey. 



